The purpose of the proposed project is to provide an opportunity for postdoctoral training in the areas of fetal neurobehavioral development, maternal stress physiology during pregnancy, and the use of psychophysiological measures in mother-infant dyads. Specifically, the project is designed to examine the gestational roots of mother-infant dyadic synchrony. Synchronous dyadic interactions are an important aspect of the mother-infant relationship and are believed to facilitate perceptual processing, secure attachment, and both physiological and affective homeostatic regulation. Recent research indicates that synchrony has its roots during the prenatal period. DiPietro and colleagues (2004; in press) have observed biobehavioral synchrony in maternal-fetal dyads that consists of temporal associations between fetal movement and maternal heart rate and skin conductance. The degree of linkage between fetal movement and maternal response is consistent across gestation and appears to represent stable individual differences between maternal-fetal pairs. The specific aims of the proposed project are 1) to determine if maternal and fetal behavioral and physiological reactivity to stress during gestation are associated with individual differences in maternal-fetal biobehavioral synchrony; 2) to determine if the degree of maternal-fetal biobehavioral synchrony during gestation is associated with individual differences in maternal physiological reactivity to child distress and maternal sensitivity during early childhood; and 3) to determine if the degree of maternal-fetal biobehavioral synchrony during gestation is related to individual differences in maternal-child behavioral and physiological synchrony during early childhood. A secondary data analysis will be conducted to determine if maternal and fetal reactivity to induced maternal stress are related to maternal-fetal biobehavioral synchrony. A follow-up is also proposed for an ongoing project to examine potential links between maternal-fetal synchrony and maternal-child synchrony during a free-play session. Maternal and child behavioral and physiological reactivity and regulation during three standardized Laboratory Temperament Assessment Battery vignettes will also be examined as potential moderators of this relationship. Research has repeatedly demonstrated the importance of early social interactions for the development of regulatory abilities and stress responsive physiology. Understanding the origins of the mother-infant relationship may have implications for interventions in the early environment that could have repercussions for both physical and mental health well into adulthood. [unreadable] [unreadable] [unreadable]